How about try the v01 concept art iteration of Ratchet from the first movie that's in a more traditional red dominant fire/rescue color scheme.

I like my ROTF desert version but I never understood why in the movies themselves, or at least one of the five voyager repaints of him weren't like this as it's a perfect fit. The side benefit is that if you want, you can pass him off as a voyager of the Decepticon Smolder from the new PCC line who's design isn't to far off. Making a suitable mini-con like Chopster to act as his fire axe accessory could be fun too.